That actually depends on time. After Panda update I would recommend that you go slowly with time. It is not better if you get thousands of backlinks within some months. That would be counted as webspam. Also sudden traffic is not good for your website SEO point of view. What matters is slow and steady performance. It also depends on the type of website you have. Backlinks are mostly generated automatically by users who register on your website. The most important aspect is to keep on adding fresh and quality content.